The invention set forth herein pertains to new and improved "toggle" type dispensing closures.
Increasingly the term "dispensing closure" has been utilized to designate closures which are adapted to be more or less permanently attached to or formed integrally with a container and which utilize a movable member which is adapted to be moved between an open position in which an opening through the closure is opened and a closed position in which the opening is closed off. This term "dispensing closure" is probably most commonly utilized in connection with closures which are adapted to be mounted upon bottles or similar containers and which utilize a spout which is adapted to be located between a closed position and an open position in which a spout is in alignment with the opening through the closure.
However, this term is also employed commonly to designate closures in which a lid is rotatably mounted so as to be capable of being moved between open and closed positions as noted. Both of these types of closures are considered to have significant commercial and utilitarian merit. At present they are most commonly formed out of a polyolefin such as a common grade of either low or high density polyethylene or polypropylene by conventional injection mold techniques. Such closures normally require assembly after their parts are manufactured by such techniques.
It is known to facilitate the assembly of a dispensing closure by forming the parts of such a closure so that they are integrally connected together either by a flexible strip or hinge-like section. Such a strap or such a hinge-like section movably or pivotally connects the parts of such a closure together in such a manner that such parts cannot be lost from one another. When such a strap or such a section is appropriately designed it can serve more or less as a guide or alignment structure to facilitate the closure parts being brought together into a final operative assembly. This is considered to be desirable from the point of view of obtaining economy of manufacture.
As the dispensing closure field has developed it has been realized that one-piece dispensing closures employing closure parts connected by a strap or hinge-like structure could be modified so as to utilize what may be referred to as a "toggle" type action. This term "toggle" is a hard to define mechanical term referring to the utilization of a first force to bias a member in either of two different positions in such a manner that a further force is required to move the member between these two positions. Frequently the first force is derived from a spring or spring means and the second force is applied so as to elongate the spring as the member is moved between such positons.
The toggle actions which have been incorporated in known one-piece dispensing closures are primarily based upon the use of a part integrally formed with such a closure as a tension member or spring which will exercise a pull so as to hold the principal parts of such a closure in either a closed or open position. Thus, for example, prior dispensing closures employing what may be referred to as a "toggle" action have utilized between a cap adapted to be attached to a container and a lid pivotally mounted upon the cap, one or more spring-like sections of polymer material extending between the cap and the lid in such a manner as to tend to hold the lid in either an open or a closed position and in such a manner that the spring-like sections have to be stretched or placed in tension to move the lid between these two positions.
Unquestionably dispensing closure structures as are indicated employing a toggle action are utilitarian. They are considered to be relatively undesirable from a commercial standpoint because of the manner in which they are constructed. In order to obtain satisfactory operational characteristics in such a closure which is relatively simple (and inexpensive) to mold by injection molding techniques it has been necessary to employ a toggle or spring member in such a manner that such a member tends to project exteriorly of a one-piece closure when the closure itself is in either an open or closed configuration, or when the closure lid is in both of these positions. It is undesirable for commercial reasons to utilize any dispensing closure which has any parts which significantly extend from the closure when the closure is closed.
This is because such extending parts are apt to become damaged during handling and/or capping operations. It is considered relatively impractical and/or difficult to mount dispensing closures having projecting parts on containers using much common capping equipment. Further, it is undesirable to have parts such as a toggle member or spring extending from the exterior of a closure when the closure is in use and is in an open position. Such extending parts tend to present an undesirable appearance. Whenever such parts extend from the closure--even when the closure is open--there is danger of such parts becoming damaged and/or interfering to a minor extent with the use of the closure.